Long-term safety and efficacy of subcutaneous immunoglobulin IgPro20 in CIDP

Abstract

ObjectiveTo investigate the long-term safety and efficacy of weekly subcutaneous IgPro20 (Hizentra, CSL Behring) in chronic inflammatory demyelinating polyneuropathy (CIDP).MethodsIn a 48-week open-label prospective extension study to the PATH study, patients were initially started on 0.2 g/kg or on 0.4 g/kg weekly and—if clinically stable—switched to 0.2 g/kg weekly after 24 weeks. Upon CIDP relapse on the 0.2 g/kg dose, 0.4 g/kg was (re)initiated. CIDP relapse was defined as a deterioration by at least 1 point in the total adjusted Inflammatory Neuropathy Cause and Treatment score.ResultsEighty-two patients were enrolled. Sixty-two patients initially received 0.4 g/kg, 20 patients 0.2 g/kg weekly. Seventy-two received both doses during the study. Sixty-six patients (81%) completed the 48-week study duration. Overall relapse rates were 10% in 0.4 g/kg–treated patients and 48% in 0.2 g/kg–treated patients. After dose reduction from 0.4 to 0.2 g/kg, 51% (27/53) of patients relapsed, of whom 92% (24 of 26) improved after reinitiation of the 0.4 g/kg dose. Two-thirds of patients (19/28) who completed the PATH study without relapse remained relapse-free on the 0.2 g/kg dose after dose reduction in the extension study. Sixty-two patients had adverse events (AEs) (76%), of which most were mild or moderate with no related serious AEs.ConclusionsSubcutaneous treatment with IgPro20 provided long-term benefit at both 0.4 and 0.2 g/kg weekly doses with lower relapse rates on the higher dose. Long-term dosing should be individualized to find the most appropriate dose in a given patient.Classification of evidenceThis study provides Class IV evidence that for patients with CIDP, long-term treatment with SCIG beyond 24 weeks is safe and efficacious.

Randomized trial of intravenous immunoglobulin maintenance treatment regimens in chronic inflammatory demyelinating polyradiculoneuropathy

“…Overall, patients who were treated with the more frequent lower IVIg dose schedule did not show more exacerbations. This suggests that high IgG peak levels are not needed for successful IVIg maintenance treatment, and this finding is in accordance with previous studies that showed SCIg could be used as maintenance treatment for CIDP [38,43]. As high peak serum IgG levels are not needed during maintenance IVIg treatment of CIDP, more personalized IVIg treatment schedules are preferred over treating all patients with expensive high maintenance dosages such as 1 g/kg every 3 weeks [44].…”

“…This might be attributable to the stable situation of the patients or mean that adverse events may not be caused by peak serum IgG levels, as has been previously suggested [37]. The long-term safety and efficacy of subcutaneous immunoglobulin (SCIg) in CIDP has been established (PATH trial) [38]. SCIg is generally given more frequently and in lower dosages than IVIg, similar to the comparison of treatment schedules in our trial.…”

Evidence of persistent improvements with long‐term subcutaneous immunoglobulin in chronic inflammatory demyelinating polyneuropathy

“…In the PATH extension study, patients who did not experience a relapse had mean change‐scores close to 0 in all measures, indicating stability as a group. However, the range of change was wide, and some patients improved by 28 centile points in the R‐ODS, by 19 points in the MRC sum score, and by 29 kPa in grip strength . Findings in the study by Cirillo et al are in keeping with the PATH extension study, providing evidence of a subpopulation of CIDP patients with continuous improvement.…”

Subcutaneous immunoglobulin proves to be an effective alternative to intravenous immunoglobulin in the treatment of chronic inflammatory demyelinating polyneuropathy

“…The extension study to the PATH trial demonstrated the long-term efficacy of SCIG and other advantages of SCIG Mr. Brown could have received such as increased independence, less time spent during subcutaneous treatment, and less felt side effects when compared with IVIG. 11 Had first-rate clinical decision science been implemented with regards to Mr. Brown's treatment he may have been offered something more compatible with his needs as a whole and not just for his medical needs.…”